Contreras-Vidal José L, Gold Daniel R
Department of Kinesiology, University of Maryland, 2363, HHP Bldg, College Park, MD 20742, USA.
Parkinsonism Relat Disord. 2004 Dec;10(8):501-6. doi: 10.1016/j.parkreldis.2004.06.002.
Parkinson's disease (PD) is widely viewed as a disorder of central motor control. However, recent studies suggest that disordered kinesthetic processing may also contribute to bradykinesia and hypometria in PD. To examine the hypothesis that abnormal kinesthesia in PD would result in impaired hand motion estimation used for motor control, we tested PD patients, elderly people, and young adults in an active, multi-joint kinesthetic-to-visual matching task. To minimize initial localization errors, visual information about the starting position was always available. The participants performed center-out drawing movements to visual targets in the absence of visual feedback of hand/pen motion at their preferred speed. Movement time (MT), end-point position error (EPE), and initial directional error (IDE) were measured. No detrimental effects of aging were observed; however, the PD group showed prolonged MTs and higher EPE scores as compared to the elderly and young groups. Principal component analysis of the end-point error distributions showed that the PD patients had larger variability in both the extent and direction axes. These results suggest that PD patients have abnormal proprioception and deficits in the central processing and integration of kinesthetic signals, resulting in the incorrect assembly of multiple sensorimotor inputs into a motor plan. It is hypothesized that altered kinesthesia in PD causes improper estimation of hand motion used for motor control due to the degraded maintenance of a dynamic internal hand representation.
帕金森病（PD）被广泛认为是一种中枢运动控制障碍。然而，最近的研究表明，感觉运动觉处理紊乱也可能导致帕金森病患者的运动迟缓及运动幅度减小。为检验帕金森病患者感觉运动觉异常会导致用于运动控制的手部运动估计受损这一假说，我们在一项主动的多关节感觉运动觉与视觉匹配任务中对帕金森病患者、老年人和年轻人进行了测试。为尽量减少初始定位误差，始终提供有关起始位置的视觉信息。参与者在没有手部/笔运动视觉反馈的情况下，以其偏好的速度向视觉目标进行中心向外的绘图运动。测量了运动时间（MT）、终点位置误差（EPE）和初始方向误差（IDE）。未观察到衰老的不利影响；然而，与老年人和年轻人组相比，帕金森病组的运动时间延长，终点位置误差得分更高。对终点误差分布进行主成分分析表明，帕金森病患者在范围和方向轴上的变异性都更大。这些结果表明，帕金森病患者存在本体感觉异常，在感觉运动觉信号的中枢处理和整合方面存在缺陷，导致多个感觉运动输入错误地组合成一个运动计划。据推测，帕金森病患者感觉运动觉的改变会导致用于运动控制的手部运动估计不当，这是由于动态手部内部表征的维持能力下降所致。
